A heat-transfer tube is generally an elongated hollow metal tube having two sealed ends. Theoretically speaking, the heat-transfer tube may have any exterior configuration. A layer of wicks is attached to an inner wall surface of the heat-transfer tube, and soaked in a working medium for the heat-transfer tube. The structure of the heat-transfer tube may vary with the amount and temperature of heat to be transferred via the heat-transfer tube.
Currently available heat-transfer tubes are made of different materials, including copper, nickel, stainless steel, tungsten, and other alloys. When the heat-transfer tube has an end positioned at a place having a higher temperature, and the other end at a place having a lower temperature, heat is transferred via the tube. Heat passes through the metal wall of the tube at the end located at the high-temperature place and into the layer of wicks, and the working medium in the wicks is heated and evaporated. Therefore, the end of the heat-transfer tube located at the high-temperature place is referred to as the “evaporator”. The evaporated working medium gathers in the hollow tube of the evaporator, and flows toward the other end of the heat-transfer tube. Since the other end of the tube is in contact with a low-temperature place, it causes the evaporated working medium reaching there to condense. At this point, the heat carried by the evaporated working medium passes through the wicks, the working medium, and the metal tube wall into the low-temperature place. Therefore, the end of the heat-transfer tube located at the low-temperature place is referred to as the “condenser”. The evaporated working medium condenses into liquid again at the condenser. The condensed working medium will then flow from the condenser back to the evaporator under a capillary pumping action. Through continuous circulating of the working medium between the evaporator and the condenser, heat is transferred from the high-temperature place to the low-temperature place. This forms the working principle of the heat-transfer tube.
The heat-transfer tube has many advantages due to its unique structure and working principle. Structurally speaking, it is a hollow tube and is therefore much lighter than a metal rod having the same volume. The heat-transfer tube has simple appearance to enable easy connection of it to other instruments. The heat-transfer tube has two sealed ends and does not need to add new working medium thereinto. It does not have any movable parts and is therefore not subjected to any wearing and is more durable for use. It does not produce any noise, either. According to the working principle thereof, the heat-transfer tube has high efficient heat-transfer ability due to the evaporation and condensation of the working medium inside the tube.
In addition, with the capillary pumping action, the fluid inside the heat-transfer tube may keep circulating without any external force even in a weight-loss condition in the space. Therefore, the heat-transfer tube is widely employed to use with radiators to effectively solve the problem of high amount of heat generated by electronic products that have very high operating speed.
FIGS. 1 and 2 shows a conventional radiating module. As shown, the conventional radiating module includes a plurality of radiating fins 11, a seat 12, and one or more U-shaped heat-transfer tubes 13. The radiating fins 11 are provided thereon with through holes 111. When the radiating fins 11 are successively and parallelly arranged, the U-shaped heat-transfer tubes 13 may be extended through the through holes 111 on the radiating fins 11 to connect to the latter. Paste tin is applied to a lower surface of the radiating fins 11 and a top surface of the seat 12, so as to connect the seat 12 to the heat-transfer tubes 13. The seat 12 has an area larger or equal to the lower surface formed from the radiating fins 11.
The above-structured conventional radiating module may be divided into two types. The first type of the conventional radiating module includes radiating fins 11 made of aluminum and a seat 12 made of copper. The radiating fins 11 must be nickel-plated before being welded to the seat 12. The second type of the conventional radiating module includes radiating fins 11 and seat 12 made of the same copper material, and can therefore be directly welded together.
Either of the two types of conventional radiating modules has problems in use. The radiating fins 11 and the seat 12 of the first type of radiating module are made of different materials and use paste tin to weld to each other. Since two materials having different heat conductivity are used, the radiating module has poor heat transfer efficiency. The use of a connecting medium, that is, the paste tin, to connect the seat to the heat-transfer tubes further adversely affects the radiating effect of the radiating module. Moreover, since the radiating fins 11 is made of aluminum and must be nickel-plated before being connected to the seat 12, the radiating module requires high manufacturing cost while has reduced rate of good yield. The second type of radiating module not only has reduced radiating effect due to the paste tin, but also overly high weight due to the copper-made large-area seat 12. Moreover, the copper-made radiating fins 11 makes the second type of radiating module 600–700 grams heavier than the first type of radiating module having aluminum radiating fins 11. The second type of radiating module is therefore too heavy to be accepted by consumers.
It is therefore tried by the inventor to develop a method of manufacturing an improved radiating module to eliminate the above-mentioned problems.